import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:photo_view/photo_view.dart';
import 'package:photo_view/photo_view_gallery.dart';

///图片放大浏览

class PhotoViewGalleryScreen extends StatefulWidget {
    List images=[];
    int index=0;
    String heroTag;
    PageController controller;

    PhotoViewGalleryScreen({Key key,@required this.images,this.index,this.controller,this.heroTag}) : super(key: key){
        controller=PageController(initialPage: index);
    }

    @override
    _PhotoViewGalleryScreenState createState() => _PhotoViewGalleryScreenState();
}

class _PhotoViewGalleryScreenState extends State<PhotoViewGalleryScreen> {
    int currentIndex=0;

    @override
    void initState() {
        // TODO: implement initState
        super.initState();
        currentIndex=widget.index;
    }

    @override
    Widget build(BuildContext context) {
        return Scaffold(
            body: Stack(
                children: <Widget>[
                    Positioned(
                        top: 0,
                        left: 0,
                        bottom: 0,
                        right: 0,
                        child: Container(
                            child: PhotoViewGallery.builder(
                                scrollPhysics: const BouncingScrollPhysics(),
                                builder: (BuildContext context, int index) {
                                    return PhotoViewGalleryPageOptions(
                                        imageProvider: CachedNetworkImageProvider(widget.images[index]),
                                        heroAttributes: widget.heroTag.isNotEmpty?PhotoViewHeroAttributes(tag: widget.heroTag):null,
                                        
                                    );
                                },
                                itemCount: widget.images.length,
//                                loadingChild: Container(),
                                backgroundDecoration: null,
                                pageController: widget.controller,
                                enableRotation: true,
                                onPageChanged: (index){
                                    setState(() {
                                        currentIndex=index;
                                    });
                                },
                            )
                        ),
                    ),
                    Positioned(//图片index显示
                        top: MediaQuery.of(context).padding.top+15,
                        width: MediaQuery.of(context).size.width,
                        child: Center(
                            child: Text("${currentIndex+1}/${widget.images.length}",style: TextStyle(color: Colors.white,)),
                        ),
                    ),
                    Positioned(//右上角关闭按钮
                        right: 10,
                        top: MediaQuery.of(context).padding.top,
                        child: IconButton(
                            icon: Icon(Icons.close,size: 30,color: Colors.white,),
                            onPressed: (){
                                Navigator.of(context).pop();
                            },
                        ),
                    ),
                ],
            ),
        );
    }
}
